Damper and an electrical energy converting device using the same

Abstract

A damper includes a resonant circuit, a damping capacitor unit and a switching circuit. A damping inductor unit of the resonant circuit receives alternating current (AC) electrical energy. A resonant capacitor of the resonant circuit is connected to the damping inductor unit. The switching circuit is connected to the resonant capacitor, the damping inductor unit, and the damping capacitor unit. The switching circuit establishes, when operating in a first phase, a connection between the damping inductor unit and resonant capacitor to store the AC electrical energy in the resonant circuit, and allows, when operating in a second phase, the AC electrical energy to be transferred to and stored in the clamping capacitor unit.

What is claimed is: 
     
       1. A damper comprising:
 a resonant circuit that includes
 a damping inductor unit having a first terminal and a second terminal, and being configured to receive alternating current (AC) electrical energy, and 
 a resonant capacitor having a first terminal that is electrically connected to said first terminal of said damping inductor unit, and a second terminal; 
 
 a damping capacitor unit; and 
 a switching circuit that is electrically connected to said second terminals of said resonant capacitor and said damping inductor unit and to said damping capacitor unit, and that is configured to operate in a first phase and a second phase; 
 wherein when operating in the first phase, said switching circuit establishes an electrical connection between said second terminals of said damping inductor unit and said resonant capacitor so as to store the AC electrical energy received by said damping inductor unit in said resonant circuit; 
 wherein when operating in the second phase, said switching circuit allows the AC electrical energy stored in said resonant circuit to be transferred to and stored in said damping capacitor unit. 
 
     
     
       2. The damper as claimed in  claim 1 , wherein:
 said damping capacitor unit has a first terminal, a second terminal and a third terminal, and includes
 a first non-polarized capacitor connected between said first and third terminals of said damping capacitor unit, 
 a second non-polarized capacitor connected between said second and third terminals of said damping capacitor unit, and 
 a polarized capacitor connected between said first and second terminals of said damping capacitor unit; and 
 
 said switching circuit includes
 a first diode set connected to said second terminal of said damping inductor unit and said first and second terminals of said damping capacitor unit, 
 a second diode set connected to said second terminal of said resonant capacitor and said first and second terminals of said damping capacitor unit, 
 a first switch unit having a first terminal that is connected to said second terminal of said damping inductor unit, a second terminal that is connected to said third terminal of said damping capacitor unit, and a control terminal, 
 a second switch unit having a first terminal that is connected to said second terminal of said resonant capacitor, a second terminal that is connected to said third terminal of said damping capacitor unit, and a control terminal, 
 each of said first and second switch units being operable in an ON state to permit current flow therethrough between said first and second terminals thereof, and being operable in an OFF state to permit current flow therethrough from said second terminal thereof to said first terminal thereof, and 
 a controller electrically connected to said control terminals of said first and second switch units, and configured to control operation of each of said first and second switch units between the ON state and the OFF state. 
 
 
     
     
       3. The damper as claimed in  claim 2 , wherein:
 when said switching circuit operates in the first phase, said first and second switch units are controlled by said controller to simultaneously operate in the ON state so as to establish the electrical connection between said second terminals of said damping inductor unit and said resonant capacitor; and 
 when said switching circuit operates in the second phase, said first and second switch units are controlled by said controller to simultaneously operate in the OFF state so as to allow the AC electrical energy stored in said resonant circuit to be transferred to and stored in said damping capacitor via said first and second diode sets and said first and second switch units. 
 
     
     
       4. The damper as claimed in  claim 2 , wherein each of said first and second switch units includes a transistor having a drain terminal, a source terminal and a gate terminal that are respectively connected to said first, second and control terminals of the corresponding one of said first and second switch units. 
     
     
       5. The damper as claimed in  claim 4 , wherein each of said first and second switch units further includes a diode having an anode and a cathode that are respectively connected to said second and first terminals of the corresponding one of said first and second switch units. 
     
     
       6. The damper as claimed in  claim 2 , wherein each of said first and second diode sets includes:
 a first diode having an anode that is connected to said second terminal of a corresponding one of said damping inductor unit and said resonant capacitor, and a cathode that is connected to said first terminal of said damping capacitor unit; and 
 a second diode having an anode that is connected to said second terminal of said damping capacitor unit, and a cathode that is connected to said anode of said first diode. 
 
     
     
       7. The damper as claimed in  claim 2 , wherein said polarized capacitor is configured to be connected in parallel with a rechargeable direct current (DC) electrical energy source so as to charge the rechargeable direct current (DC) electrical energy source. 
     
     
       8. The damper as claimed in  claim 1 , wherein said damping inductor unit is configured to be connected to an isolation transformer for receiving the AC electrical energy therefrom, serves as a transformer when interacting with the isolation transformer, and serves as an inductor when interacting with said switching circuit. 
     
     
       9. An electrical energy converting device comprising:
 a direct current (DC) to alternating current (AC) converter including
 a DC-AC converting circuit that is configured to be electrically connected to a DC electrical energy source for receiving DC electrical energy therefrom, and that converts the DC electrical energy into AC electrical energy, and 
 an isolation transformer that has an input port electrically connected to said DC-AC converting circuit for receiving the AC electrical energy therefrom, and an output port, and that outputs the AC electrical energy at said output port thereof; and 
 
 a damper including a resonant circuit, a damping capacitor unit and a switching circuit; 
 wherein said resonant circuit includes
 a damping inductor unit having a first terminal and a second terminal, and electrically connected to said output port of said isolation transformer for receiving the AC electrical energy therefrom, and 
 a resonant capacitor having a first terminal that is electrically connected to said first terminal of said damping inductor unit, and a second terminal; 
 
 wherein said switching circuit is electrically connected to said second terminals of said resonant capacitor and said damping inductor unit and to said damping capacitor unit, and is configured to operate in a first phase and a second phase; 
 wherein when operating in the first phase, said switching circuit establishes an electrical connection between said second terminals of said damping inductor unit and said resonant capacitor so as to store the AC electrical energy received by said damping inductor unit in said resonant circuit; and 
 wherein when operating in the second phase, said switching circuit allows the AC electrical energy stored in said resonant circuit to be transferred to and stored in said damping capacitor unit.